A. Field of the Invention
The present invention relates to a gateway apparatus that converts communication protocols between two networks having differing communication protocols. Specifically, the present invention relates to a gateway apparatus that effects communication between a circuit-switched network and a packet-switched network. The present invention further relates to a terminal specification method for such a gateway apparatus, and a computer-readable recording medium having recorded thereon a terminal-specifying program configured to operate such a gateway apparatus.
In the description below of present invention, the term xe2x80x9cpacket-switched networkxe2x80x9d refers generally to networks that use packet-switching in the transmission of data. Such packet-switched networks include, for instance, the Internet, Intranet and local area networks (LAN). Further, the term xe2x80x9cinformation terminalxe2x80x9d refers to a unit that can be connected to another unit on a packet-switched network and can transmit and receive packets to and from a gateway apparatus and connect and disconnect to and from the gateway apparatus in accordance with the present invention.
B. Description of the Related Art
The so-called xe2x80x9cInternet telephonexe2x80x9d is a voice communication service on the Internet and has recently gained popularity. In most cases at present, the Internet telephone system is operated in such a manner that each of communicating terminals has an Internet telephone protocol and is connected directly to the Internet. However, as the Internet telephone becomes more and more popular, attention is being paid increasingly to a gateway that connects a circuit-switched network to the Internet or the like. That is, the gateway provides a connection to permit communications between a client who is, e.g., a resident individual connected to a circuit-switched network such as a PSTN (Public Switched Telephone Network) and a client who is, e.g., a corporation directly connected to the Internet.
Some of the problems the present invention seeks to solve are discussed below.
To allow an incoming call from a circuit-switched network to arrive at a packet-switched network such as the Internet by using a conventional gateway, a client on the circuit-switched network must call the gateway once and then input the identifier (equivalent to the telephone number) of a client on the Internet again in accordance with a guidance or a dial tone.
An object of the present invention is to provide a gateway apparatus, a terminal specification method for the gateway apparatus and a computer-readable recording medium having recorded a terminal-specifying program, which facilitate the calling operation performed by a calling party on a circuit-switched network by specifying a client on a packet-switched network to which the calling operation is directed when the circuit-switched network and the packet-switched network are connected to each other.
In accordance with one aspect of the present invention, a gateway apparatus connects a packet-switched network to a circuit-switched network. The packet-switched network has a plurality of information terminals connected thereto. Such gateway apparatus includes recognition means, incoming call notification means and connection means. The recognition means recognizes information terminals on the packet-switched network. The incoming call notification means notifies all the recognized information terminals of a call when receiving an incoming call from the circuit-switched network. The connection means connects the circuit-switched network to the information terminal that responds first to the incoming call notification such that voice data of the incoming call is transmitted between the circuit-switched network and the information terminal via the gateway apparatus.
That is, when the gateway apparatus receives an incoming call from the circuit-switched network, the gateway apparatus notifies all the recognized information terminals of the call, and connects to the circuit-switched network the information terminal that has responded first to the call to establish the communication between the two. The calling party on the circuit-switched network can call an information terminal on the packet-switched network by inputting an identification number (e.g., telephone number) only once.
A second aspect of the present invention provides a gateway apparatus, in which the incoming call notification means notifies all the information terminals on the packet-switched network of a call in a point-to-multipoint communication manner using a broadcast address when receiving an incoming call from the circuit-switched network.
By using a broadcast address that designates all the information terminals on the packet-switched network as a destination or called IP address, the gateway apparatus notifies all the information terminals of an incoming call in a point-to-multipoint communication manner, and connects to the circuit-switched network an information terminal that has responded to the incoming call notification first. Thereby, voice data may be transmitted between the circuit-switched network and information terminals via the gateway apparatus.
A third aspect of the present invention provides a gateway apparatus, in which the incoming call notification means notifies a plurality of information terminals on the packet-switched network of a call in a point-to-multipoint communication manner using a multi-cast address when receiving an incoming call from the circuit-switched network.
By using a multi-cast address that specifies a plurality of information terminals among the information terminals on the packet-switched network as a destination address, the gateway apparatus notifies a plurality of information terminals of a call in a point-to-multipoint communication manner. The gateway apparatus thereafter connects to the circuit-switched network an information terminal having responded to the incoming call notification first.
A fourth aspect of the present invention provides a gateway apparatus, in which the recognition means allocates the order to each of the information terminals, and the incoming call notification means notifies each of the information terminals of a call in accordance with the order that has been allocated thereto when receiving an incoming call from the circuit-switched network, and continues to send the incoming call notification until a response to the incoming call notification is received.
For example, an appropriate order of notification, e.g., an alphabetical order of the names of the information terminals is specified, and the gateway apparatus notifies the information terminals of an incoming call in such specified order. When an information terminal has responded to the incoming call notification, the gateway apparatus connects such information terminal to the circuit-switched network, and when the information terminal has not responded to the incoming call notification, the apparatus notifies an information terminal that is supposed to take its turn next of the call.
A fifth aspect of the present invention provides a gateway apparatus in which the recognition means allocates source-identifying information to each recognized information terminal. The source-identifying information provides a means for identifying a specific information terminal via, for instance, a portion of the telephone number provided from the circuit-switched network. The communication notification means selects an information terminal corresponding to identification from the source-identifying information. The communication notification means then notifies the selected information terminal of an incoming call when receiving an incoming call corresponding to the source-identifying information from the circuit-switched network.
The recognition means allots telephone numbers, or the like to the information terminals that it has recognized. When receiving an incoming call accompanying the telephone number (calling party number), the incoming call notification means selects an information terminal allotted to the telephone number from the recognized information terminals, and notifies the selected information terminal of an incoming call. For example, for incoming calls from a long-distance telephone number such as those numbers beginning with the digits xe2x80x9c06xe2x80x9d, an incoming call notification is sent to information terminals A and B, and for other calls, an incoming call notification is sent to an information terminal C.
A sixth aspect of the present invention provides a gateway apparatus, in which: a gateway supports a plurality of lines on the circuit-switched network; and the recognition means allots any one of the plurality of lines to each of the recognized information terminals; and when receiving a call directed to one of the plurality of lines from the circuit-switched network, the incoming call notification means selects an information terminal allotted to the line to which the call is directed and notifies the selected information terminal of an incoming call.
For example, let us assume that the gateway apparatus supports two lines on circuit-switched network. The recognition means allots either one of the two lines to information terminals that it recognizes. The incoming call notification means sends an incoming call notification to an information terminal allotted to the line to which the call is directed.
A seventh aspect of the present invention provides a gateway apparatus, in which: the information terminals and the gateway apparatus can handle character communication with each other by using an application for executing character communications substantially on a real-time basis; the incoming call notification means notifies the recognized information terminals of an incoming call by means of character communication when receiving an incoming call from the circuit-switched network; and the connection means in the gateway apparatus connects the information terminal that responds first to the circuit-switched network.
An exemplary application for executing character communications is xe2x80x9cInternet Relay Chat (IRC).xe2x80x9d The incoming call notification means transmits an incoming call notification command, e.g., xe2x80x9cSET UPxe2x80x9d to a chat channel. On the other hand, a specific command, e.g., xe2x80x9cCONNECTxe2x80x9d indicating a willingness to connect, is inputted at an information terminal in response to an incoming call notification, the connection means detects the command xe2x80x9cCONNECTxe2x80x9d and connects the information terminal that has inputted such command to the circuit-switched network.
An eighth aspect of the present invention provides a gateway apparatus, in which: at least one of the information terminals is a telephone message recorder terminal having communication recording means and being always available; and the connection means in the gateway apparatus connects the telephone message recorder terminal to the circuit-switched network if there is no response from any one of the information terminals to which an incoming call notification has been sent such that voice data may be communicated therebetween by the gateway apparatus.
If none of the information terminals to which the incoming call notification is sent has responded, the connection is established between the telephone message recorder terminal and the circuit-switched network to make a recording of caller""s message, images and the like.
A ninth aspect of the present invention provides a gateway apparatus, in which the recognition means recognizes available information terminals.
The recognition means stores information terminals that are available by providing, e.g., a client management list. The incoming call notification means notifies the information terminals stored in the client management list of an incoming call, so that wasteful incoming call notifications addressed to unavailable information terminals can be eliminated.
A tenth aspect of the present invention provides a gateway apparatus, in which: the recognition means maintains available status of the recognized information terminals; and the incoming call notification means notifies information terminals whose status is such that they are available for receiving an incoming call.
For example, all the information terminals on the packet-switched network are stored in the client management list or the like, and the status of each information terminal, whether it is available or not, is updated and stored in accordance with a notification from each information terminal. The incoming call notification means and the connection means notifies an available information terminal of an incoming call and establishes the communication.
An eleventh aspect of the present invention provides a terminal specification method used for a gateway apparatus that connects a packet-switched network to a circuit-switched network, the packet-switched network having a plurality of information terminals connected thereto. The method includes the steps of: recognizing information terminals on the packet-switched network; notifying the recognized information terminals of an incoming call when an incoming call is received from the circuit-switched network; and connecting to the circuit-switched network the information terminal that has responded first to the incoming call notification.
This aspect of the invention has an operation similar to that of the first aspect of the invention.
A twelfth aspect of the present invention provides a computer-readable recording medium having recorded a terminal-specifying program used for a gateway that connects a packet-switched network to a circuit-switched network, the packet-switched network having a plurality of information terminals connected thereto. The recording medium has recorded the terminal-specifying program that executes the following steps A, B and C.
Step A is a step of recognizing information terminals on the packet-switched network.
Step B is a step of notifying the recognized information terminals of an incoming call when an incoming call is received from the circuit-switched network.
Step C is a step of connecting to the circuit-switched network the information terminal that has responded first to the incoming call notification.